This invention relates to printers, and in particular, to a method and apparatus for adjusting the position of a printhead in a printer relative to different-thickness print media.
A typical inkjet printer includes one or more print cartridges which include printheads through which ink is ejected as the cartridges reciprocate across a print-medium travel path along which various print media travel through the printer. In most conventional printing situations, such print media typically includes both conventional plain paper having one thickness, and envelopes having a slightly greater thickness. In order to achieve crisp, high-quality printing, without smearing, which can occur if a printhead touches or comes too close to underlying print media, it is important that the spacing between the printhead and the surface of the underlying media have a certain predetermined spacing. Where media differing in thickness are to be handled (and such is usually the case, for example, where conventional single-sheet paper and thicker envelopes are printed upon), a single, fixed printhead to travel-path spacing is not ideal. Such a spacing typically defers to the expected greater-thickness envelope media, and this deference comprises print quality and crispness for thinner single-sheet paper media.
The present invention provides apparatus for adjusting the spacing in a printer between a printhead and the travel path for print media which moves through the printer. The printhead is borne by a carriage which is rotatably mounted adjacent an elongate bearing rail wherein the rotated condition of the carriage relative to that rail establishes the desired spacing. First and second relative moveable bearing structures mounted on the carriage include bearing surfaces which can alternatively adjust the bearing structures so that one or the other determine the rotated condition of the carriage